Ten Elements of Orienteering - Compass Skills

posted 14 Jun 2014, 11:14 by Elaine Sheridan

We hope you didn't have to put the Relocation technique demonstrated in last weeks video into practise in Walshtown on Tuesday evening. This week's Ten elements of orienteering video focuses on - Compass Skills.

This is the fifth in a series of short training videos produced by the Irish Orienteering Association to help you learn the skills needed to orienteer. This video explains Compass Skills. We hope you enjoy the video and if you want anyone to further demonstrate this technique just ask any of our experienced club members at our event in James' Fort on Tuesday evening. You will find them at registration and at the start.

Although the most important navigational aid used in orienteering is the human brain, one other navigational device which is allowed and is in general use is the compass. Compasses are useful for taking bearings and for orienting the map so that it is aligned with the terrain - but it is possible, in most areas, to complete a course quite easily and efficiently without a compass (an exception would be a flat area poor in prominent features). The compass needle is painted in two colours. Assuming that the compass is held flat, the red end points to magnetic north and the white end to magnetic south.

Compass TypesThere are two main types of orienteering compasses:

The Baseplate or Protractor Compass

This type of compass was invented by the Kjellstrom brothers during the World War II era and consists of a rectangular baseplate, which is marked with a red arrow pointing along the long axis, and a rotating compass housing marked in degrees. Marked on the floor of the rotating compass housing are an arrow and a set of lines parallel to that arrow. Additional features may include a lanyard for attaching the compass to the wrist, scale bars for measuring map distances along one or more edges of the baseplate, a magnifying glass for reading fine map detail, and templates of a circle and triangle for marking orienteering courses on the map.

The Thumb Compass

In the mid 1980s, a top Swedish orienteer developed an alternative to the baseplate compass by reshaping the baseplate and adding a strap for attaching the compass to his thumb. This compass is then placed on the thumb of the left hand, which holds it on the map. The advantage of this system is that the map and compass are always read as a unit, the map is aligned more easily and quickly, plus one hand is left free; the disadvantage is that running very accurately on a bearing is more difficult. Personal preference usually determines the type of compass that is used.

Compass SkillsUsing either type of compass, there are two basic skills an orienteer needs:

Orienting the map

This is a simple skill and is probably the most important use of the compass:

Hold your map horizontally.

Place the compass flat on the map.

Rotate the map until the "north lines" on the map (a series of evenly spaced parallel lines drawn across the map, all pointing to magnetic north) are aligned with the compass needle.

The map should now be oriented to the terrain. This makes it much easier to read, just as text is easier to read the right side up than upside down.

Taking a bearing

Every direction can be expressed as an angle with respect to north. Bearings are expressed as a number of degrees. Orienteers take the easy way out, by just setting the angle on their compass and keeping the needle aligned, which in turn keeps them going in the right direction. A simple set of step-by-step instructions for setting a bearing on a baseplate compass is given below:

Place the compass on the map so that the direction of the travel arrow is lined up with the way you want to go.

Turn the compass housing so that the arrows engraved in its plastic base are parallel to the north arrows drawn on the map (make sure the arrowhead points north and not south).

Take the compass off the map and hold it in front of you so that the direction of the travel arrow points directly ahead of you.

Rotate your body until the compass needle is aligned with the arrow on the base of the compass housing.

Pick out a prominent object ahead of you along the direction of travel, go to it, and repeat the process (this way you can detour around obstructions but still stay on your bearing).